Shelf tags have been used for many years to display pricing information in association with the shelving on which various products are displayed for purchase. Along with pricing information, shelf tags may include additional information including bar codes representing a product on the shelf which can be used for inventory control, as well as product information or additional material. Such shelf tags have conventionally been simply constructed of a paper material on which pricing and product information is printed, which can then be placed directly on the shelving adjacent the product to which it pertains. Shelving associated with the display of product in supermarkets and other retail stores have been designed to accommodate shelf tags, with these types of shelf tags placed within a flexible plastic casing which can be snap fit onto a shelf at an appropriate position. The plastic case allows the shelf tag to be easily removed and replaced to update pricing or other information when needed.
Although serving the desired purpose, these types of shelf tags are somewhat cumbersome in use, in that updating of the pricing information requires physical removal and replacement of the shelf tag, which for retail environments becomes time consuming and expensive. Further, updating of pricing or other information on the shelf tag requires complete replacement, necessitating continuous repurchasing of new shelf tags with properly printed updated information thereon. These characteristics of the shelf tag also result in a risk that pricing or other information is not updated accurately or the shelf tags are not replaced properly.
The above problems with common shelf tags have led to the development of electronic shelf tags. Current electronic shelf tags implement the simple function of displaying information, such as a goods price, in a complicated and expensive manner. Known electronic shelf tags require an electronic display such as a liquid crystal display (LCD), display driver circuitry, programming interface circuitry, an independent power source, and other miscellaneous control circuitry to accomplish this simple function. One major drawback to the prior art devices is that the shelf tag must continuously be supplied with power to maintain its display. The power necessary to maintain the display has thus limited the amount of information which can be reasonable displayed and requires frequent replacement of a battery power supply. Also the addressing schemes used to write information onto typical LCD displays requires many connections making it necessary to incorporate the interface and driver circuitry directly into the shelf tag. Additionally, due to the sensitive nature of electronics to environmental conditions and LCD displays typically being made with glass, the known shelf tags are fragile and can be easily damaged by unconcerned shoppers or others unaware of the devices frail structure.
Also, to program and change the information displayed in known electronic shelf tags, a fixed connection between the shelf tag and the programming device must be maintained which is inconvenient and time consuming for persons assigned to change the information. Additionally, the shelf tags would require additional memory circuitry in order for a programming device to monitor the current value being displayed before writing new information over it. This function would be critical to an inventory control system.
Further to the above deficiencies of known electronic shelf tags, a main problem is associated with their cost. With all of the necessary additional circuitry and constant power requirements, current electronic shelf tags are prohibitively expensive, particularly for large -stores that would require hundreds of tags from using the electronic shelf tags in place of standard paper shelf tags.